1. Field of the Invention
The invention relates to a method for emptying the pressure medium from a hydraulic unit of a hydraulic brake system of a motor vehicle.
2. Description of the Prior Art
Increasingly, motor vehicles are being equipped with traction-controlled hydraulic brake systems. In disposing of vehicles that have been in accidents or are too old, however, there is no usable way of removing and disposing of the pressure medium contained in the brake system and especially in the hydraulic unit of the traction control system. In the case of the hydraulic unit, this is especially difficult because elecromagnetically actuatable valves are built into it, which when without current assume their blocking position and therefore make lines in the unit impassable. It is therefore the object of the invention to create an effective method for emptying the hydraulic unit that can be performed in a simple way.
The method of the invention is advantageously distinguished in that by simple aids, given a suitable long action time, adequate emptying of the pressure medium from the hydraulic unit is achieved. In particular, it is advantageous to use a permanent magnet, because under the rough operating conditions in a disposal facility, it would not be expedient to switch the valve over electromagnetically.
In accordance with one embodiment of the invention an accelerated and more-effective emptying of the hydraulic unit is attained, if valves are disposed in parallel lines and assume different switching positions.
In accordance with another feature of the invention, adequate emptying of the entire brake system is advantageously achieved.
Conversely, if pressure medium is to be eliminated from the hydraulic unit independently of the brake system, then in accordance with another feature, an additional advantage is achieved in that because of the closed lines, when the hydraulic unit is removed from the motor vehicle no pressure medium can escape and pollute the environment.